ing of first principles, which habit is from
nature: wherefore also first principles are said to be known
naturally.

_I answer that,_ One thing can be natural to another in two ways.
First in respect of the specific nature, as the faculty of laughing
is natural to man, and it is natural to fire to have an upward
tendency. Secondly, in respect of the individual nature, as it is
natural to Socrates or Plato to be prone to sickness or inclined to
health, in accordance with their respective temperaments. Again, in
respect of both natures, something may be called natural in two ways:
first, because it entirely is from the nature; secondly, because it
is partly from nature, and partly from an extrinsic principle. For
instance, when a man is healed by himself, his health is entirely
from nature; but when a man is healed by means of medicine, health
is partly from nature, partly from an extrinsic principle.

Thus, then, if we speak of habit as a disposition of the subject in
relation to form or nature, it may be natural in either of the
foregoing ways. For there is a certain natural disposition demanded
by the human species, so that no man can be without it. And this
disposition is natural in respect of the specific nature. But since
such a disposition has a certain latitude, it happens that different
grades of this disposition are becoming to different men in respect
of the individual nature. And this disposition may be either entirely
from nature, or partly from nature, and partly from an extrinsic
principle, as we have said of those who are healed by means of art.

But the habit which is a disposition to operation, and whose subject
is a power of the soul, as stated above (Q. 50, A. 2), may be natural
whether in respect of the specific nature or in respect of the
individual nature: in respect of the specific nature, on the part of
the soul itself, which, since it is the form of the body, is the
specific principle; but in respect of the individual nature, on the
part of the body, which is the material principle. Yet in neither way
does it happen that there are natural habits in man, so that they be
entirely from nature. In the angels, indeed, this does happen, since
they have intelligible species naturally impressed on them, which
cannot be said of the human soul, as we have said in the First Part
(Q. 55, A. 2; Q. 84, A. 3).

There are, therefore, in man certain natural habits, owing their
existence, partly to nature, a